Gene mutation spectrum of 270 patients with gastrointestinal stromal tumor and its association with clinicopathological features

Abstract:

Objective：To investigate the feature of c-kit and platelet-derived growth factor receptor α（PDGFRA） gene mutation in 270 patients with gastrointestinal stromal tumor（GIST），as well as its association with clinicopathological features. Methods：The gene detection result and clinicopathological data of 270 GIST patients，who underwent treatment in our hospital from June 2016 to January 2019，were collected retrospectively. Results：Among 270 patients，220 patients had c-kit mutations which were mainly oc－curred in exon 11，and then exon 9. Multimutation of A502-Y503 was the unique genotype for exon 9. Deletion mutation and point mutation were the most common mutations in c-kit exon 11，which mainly occurred in location of 557-560. Among seven patients with PDGFRA mutation，D842V mutation in exon 18 was the most common type. Among all c-kit 11 mutations，the rate of point mutation or mixed mutations occurred in the stomach was lower than that of other mutation types（P=0.022）. In patients with c-kit 11 mutations，the frequency of patients who were older than 50 years was more than other c-kit exon mutations（P=0.040）. The rate of c-kit exon 9 mutation in the small intestine was higher than other mutations（P=0.000）. The rate of mitotic count<5/50 HPF in patients with PDGFRA mutation and wild type was higher than that in c-kit mutation patients（P=0.027）. CD117 positive rate in c-kit mutation patients was significantly higher than that in PDGFRA mutation and wild type patients（P=0.000）. SMA positive rate in wild type patients was higher than that in mutation patients（P=0.002）. Conclusion：GIST patients have high frequency to expe－rience c-kit/PDGFRA；mutation locations and types are closely correlated with clinicopathological features，which also are impor－tant judgements for individual treatment.